Sixteen years ago, I probably wouldn't have had much to say. We had no treatments at all, nothing to offer. Now we at least have modest treatments and in the last 10 years, we've really honed in on the cause of Alzheimer's.

I would tell a patient now that we are actively pursuing many promising approaches for altering the course of disease and ultimately halting it. I would invite them to volunteer for Alzheimer's studies, not so much as a way to get access to treatments, but to join the effort to move the science forward.

Can you prevent Alzheimer's?

We don't know what is effective as a preventive measure for Alzheimer's. A huge amount has been written on the topic, but nobody really knows what is useful. We have hints from epidemiological studies, from seeing who has the disease and who doesn't, from looking back and teasing apart the differences in these populations.

But such studies are never definitive, and they're prone to many confounding factors. Epidemiological studies are often wrong. A given answer may turn out not to be correct. That's why you can read one week to do this and next week be told to do something different.

Still, there are some basic things everybody should do: Be active. Stay cognitively active, socially active. These things seem to be associated with reduced risk of Alzheimer's. People who continue to learn, to read, to discuss, who exercise, watch their weight and things like blood pressure and cholesterol level, they appear to be at reduced risk.